1. Field of the Invention
This invention generally relates to control of photo or a video camera and, more particularly, to selecting the focus, exposure, white balance, or any other automatic camera control, in the viewfinder or image display area of analog and digital still and video cameras.
2. Description of Related Art
Modern cameras, such as film point-and-shoot cameras, film single-lens-reflex cameras (SLR), digital point-and-shoot cameras, and digital SLR cameras, include a number of built-in sensor options that assist camera users with the photographic process. Examples of these options include automatic focus, automatic metering with automatic aperture and/or shutter speed control and automatic white balance adjustment.
In modern cameras, despite the fact that focus, metering, and the like are automated, the automation is not applied indiscriminately. For example, in a camera with multiple autofocus points, a user often has two choices: (1) let the camera automatically select multiple focus points to put the entire scene into focus, or (2) let the photographer manually select a single autofocus point or region which includes multiple contiguous points, and use the single point or region for autofocus. Similar interfaces exist for metering, and to a lesser extent for white balance; the user may either select all metering zones or one metering zone. The above conventional methods are referred to as A-DEP, for automatic depth of field, and DEP, for simply depth of field, and are further described below.
The problem is that these two choices often do not allow the user sufficient control. A single focus point might put the primary subject or the front of a subject into focus, but leave the secondary subject blurred. On the other hand, a camera-selected all-focus-points option while putting both the primary and secondary subjects in focus may put the background into focus, as well. This is usually undesirable as one often wishes to isolate the background from the main subjects of the photograph in order to achieve a more desirable overall photographic composition.
A third option, provided in certain cameras with a depth of field mode option, allows the photographer to point the camera towards a first point of focus and indicate this point to the camera and then towards a second point of focus and indicate the second point to the camera as well. The camera provides autofocus on the image based on the two points provided to the camera sequentially. However, this approach requires extra time and effort on the part of the user.
Thus, the conventional industry approaches are deficient in their ability to facilitate speedy selective focusing on subjects in analog and digital still and video cameras.